Homework Help: Limit problem involving 1-sided limits

1. Sep 15, 2012

Bipolarity

1. The problem statement, all variables and given/known data
$$\lim_{a→0+}\frac{1}{a}- \lim_{b→0-}\frac{1}{b}$$

2. Relevant equations

3. The attempt at a solution
I assume I would have to use the Cauchy definition of a limit to solve this, but I was wondering if there were any alternative ways.

BiP

2. Sep 16, 2012

susskind_leon

You cannot solve this at all, because neither of the two limits exist. Thus you cannot carry out the substraction.

3. Sep 17, 2012

damabo

hmm personally I would say the first term gives +infinity and the second term gives - infinite; so subtracting the two would give +infinity. why is this wrong?

4. Sep 17, 2012

susskind_leon

Damn, I guess you're right ;-)